Short video platforms, with their ease of content production, wide dissemination, and large user base, have become important mediums in the internet, providing new opportunities for film marketing and promotion. This study explores the use and effects of short video platforms (Douyin) in film marketing. Through case analysis and in-depth interviews, short video marketing has significant advantages in disseminating film information, attracting audiences with diverse content forms, and increasing exposure and appeal. However, issues like excessive plot leakage and content homogenization may affect audience expectations and viewing experience. The study also reveals that short video marketing excels in emotional resonance and guiding social topics but should avoid over-reliance on star power and misleading promotions. Based on these findings, the study recommends optimizing short video film marketing strategies, including maintaining content novelty, enhancing emotional marketing, effectively using audiovisual language, and accurately targeting audiences to improve marketing effectiveness and audience engagement.